Percussion tool



March 1l, 1952 c. T. COLE PERCUSSION TOOL 5 Sheets-Sheet l Filed June 9, 1950 MLY/Ay L March 1l, 1952 cQ-r. coLE PERCUSSION TooL 5 Sheets-Sheet 2 Filed June 9, 195C IN1/EN TOR. War/e5 .7 60/6,

M, 2&7 Y M Arm/wrs March 1l, 1952 C, T, COLE 2,588,360

PERCUSSION TOOL Filed June 9, 1950 3 Sheets-Sheet C5 |40 199 20 21", f if l] l @A l l l o I y 64d Fi .l0

i JNVENTOR. 'af/es Zo/et W ATTORNEYS Patented Mar. 11, 1952 UNITED STATES PATENT DFFICE PERCUSSIQN TOOL Chartes T. Cole, New Philadelphia, Ohio Application J une 9, 1950, Serial No. 167,236

"5) Claims. l

My 'invention relates to agpercussion tool. 'It has y"to do, more particularly, with a percussion tool or'hammer of that general type wherein the hammer or striking `member is driven by mechanical means ratherthan pneumatic means.

One of the objects of my invention is to provide a very simple and inexpensive percussion tool whichiis of small and compact structure and, therefore, is portable.

Another object 'of my invention'is to provide a"'percussion 'tool 'which is mechanically vdriven rather 'than pneumatically driven so that it is not necessary "topro'vide'a compressor for operating it.

Still another object of 'myinvention is to'provide apercussion tool of the type indicated which isfprovided with 'simple means yfor rotating the toolereceiving chuckthereof after each impact of 4the hammer.

An additional object ofmyinvention is to provide a percussion tool vvwhich 'is provided with means "forcompressing air each time the `hammeris actuated, the compressed air 'being directedito the itool-carrying "chuck and 'being useful, for exampleyin connection with a grill to blow out loosened :material from the `hole being drilled.

Still another object of my invention is toprovide a percussiontool of the type indicated in the'preceding'paragraph which is provided with an arrangement that 'may be used'to iSupply liquid to the hole'beingfdrilled.

Various other objects `'will be apparent. According to rmyinvention, I provide a'percussion tool "which includes va cylindrical housing 'having `a handle-carryingiradial extension at one end thereof. `Within the radial extensionI provvide 'apower unit, such as ian electric motor or electromagnetic `drivin-g means.

Within the cylindricalpart of the housingl provide a recipro- "cable rod or plunger, the forward end of which `servesas the hammer `or striking element. The `rear end of the irodis .connected by a crank 'arrangement Lito the fpower element 'sothat it will be reciprocatedthereby. The forward endoi the rod, 'that is, 'the hammer, is adapted to strike ber.` carries "the"tolereceiving chuck. `Associated with the :rod 'or plunger within `the :cylindricali` 'housing isa `piston member which is so arranged that itfcompresses iair within'the housing `each "tinievthe rodlmove's forwardly to cause thehamnier Vto strike the anvil. .The compressed `lair,

thus created, .isidirected through ltheitoolechuck l 2 and into a drill, for example, to remove loosened material 'from the drilled hole. Associated with the air compressing means is a water inlet `so that water can enter the housing and be forced to the drilling tool when desired. Ratchet mechanism is associated with the anvil for rotating it step by step so that the drill will be rotated to a new position each time the hammer strikes the anvil. This ratchet mechanism is actuated by means of a screw arrangement which is turned in the proper direction as the rod moves it rearwardly after each impact of the hammer by means of a proper actuating connection between the rod and the screw.

The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure l is a longitudinal vertical sectional View taken through my percussion tool, the plunger and hammer being shown in withdrawn position.

Figure 2 is a view similar to Figurel but showing the hammer in anvil-striking position.

Figure 3 is a horizontal sectional view through the structure of Figure 1.

Figure 4 is a transverse sectional view taken on line 4--4 of Figure 1.

Figure 5 is a sectional view taken online 5-5 of Figure 4.

Figure 6 is a similar view Vtaken on line (u1-Bof Figure 4.

Figure '7 is a transverse sectional view taken on line 1-1 of Figure 1.

Figure 8 is a detail, in perspective, of `the ratchet means for rotating the anvil and the screw for actuating the ratchet means.

Figure 9 is a perspective view of my tool.

Figure 10 is a verticalsectional view through a modified typeof tool.

With reference to the drawings, Ihave illustrated the general structure of my percussion tool in Figures 1 to 3 and 9. The tool includes the cylindrical housing I I which is connected at its rear end to a radially extending housing portion I2. As shown in Figure 9, this extension I2 may be provided with outwardly extending handgrips i3 `at opposite sides thereof.

Within the extension l2, I provide suitable power means, for example, an electric motor I4, which is bolted at I5 to the sides of the extension. This motor I4 is adapted to reciprocate a rod or plunger I6 which is axially supported within the Acylindrical housing .portion II. The frod or plunger I6 `is mountedfor :sliding movementin bushing I I and AI8 4,disposed .at the axis :of the guiding and supporting disc-like members I9 and 20 which are disposed in fixed axially spaced relationship within the portion Il of the hous- In order to connect the motor l@ to the rod Iii, I provide the crank arrangement illustrated best in Figures 1 to 3. It will be noted that the housing extension l2 is provided with a support 2| which rotatably supports a gear 22 in crank disc 23 which are formed as a combined unit. The gear 22 is driven from the drive shaft of the motor by suitable reducing gearing including the double pinion unit 2d carried by the support 2i. Pivoted at an eccentrically disposed point by a pivot pin 2da is one end of the pitman-25. The opposite end of this member 25 is connected by a universal joint 25 to the rear end of the rod if. Thus, when the crank disc 23 is rotated by the motor i d, the rod l is reciprocated axially within the guide members le and 2i?.

Fixed on the-rod i5 is a piston 2li which moves with the rod relative to the cylindrical housing l l between the guide members l@ and A compression sp-ring 253 is provided between member I9 and piston 2l. Similarly, a compression spring 29 is provided between the piston 2l and member 2S. Thus, when the piston is moved in either direction by means of the crank mechanism one of the springs 28 or 29 is compressed and the other is permitted to expand. These springs serve to cushion the movement of the pieton and eliminate the necessity of accurate adjustment of the stroke of the rod l5.

It will be noted that the members i9 and 2! serve to form a cylindrical chamber 35i within housing l l and between such members. It will be noted that at the rear end of this chamber 3E an air inlet 3l is provided in the wall of housing i l. It will further be noted that the member 2t is provided with a plurality of bores 32 therethrough which serve as air outlets for chamber The piston 2l is provided with a plurality of bores 53 extending therethrough. On the forward side of the piston a valve plate 34 is provided for closing the forward ends of all of these bores 33. It will be noted from Figures 4, 5 and 6, that the valve plate 36 is carried by pins 35 which are mounted for axial movement in bores Sii in the piston The pins 35 will move axially to space the valve plate 34 from the front surface of the piston, shown by dotted lines in Figure 6, the rear ends of the pins 35 being provided with stops 3l to engage the rear surface of the piston and limit forward movement of plate S4.

ne mechanism just described serves as a small compressor for providing a supply of compressed air. During rearward movement of piston 2l, the valve plate 3d is unseated and air which has been taken into the rear end of chamber 38 through opening 3| is forced forwardly through openings 33 in the piston to the forward side of the chamber 3S. During forward movement of the piston, this air in the forward portion of the chamber 3d is compressed by movement of the piston and the air pressure developed moves the plate ed rear wardly until it is seated on the front face of the piston. Further forward movement of the piston, further compresses the air, and forces it from chamber 3c through the openings 32 into the forward end of the housing l l. The air is conducted from the forward end of housing l l in a manner to be described.

At the forward end of the housing l l, an anvil member 38 is rotatably and reciprocably mounted. This member 38 is provided with an enlarged portion 39 which rits snugly within the enlarged forward end lil of the housing Il. A stop shoulder il on the housing limits inward movement of piston 38. The anvil 3S is provided with a forwardly extending tool-receiving chuck l2 and with a rearwardly extending striking portion 3. The striking portion 43 is adapted to be engaged by the hammer or striking portion 44 on the forward end of the rod I5. A compression spring t5 is provided ahead of the enlarged portion te of the anvil in surrounding relationship to the chuck portion t2. This spring'l engages a cap is which is threaded into the forward end of the housing portion fie. The cap 4S is provided with a central opening fil through which a tool T may extend and may move axially and rotate, this tool, for example, may be a drill. The tool is provided with a shoulders with which a retaining member i3 may cooperate. This retaining member i8 is provided with a yoke de which normally engages tre tool and prevents it from dropping from the tool-receiving socket 5Fl in chuck 42. The retaining member 4S is pivoted at 5l to opposed sides of the housing portion [lil and is normally kept in engagement with the tool T by means of a spring 52 associated with one of the pivots 5i.

It will. be apparent that upon forward movement of rod if?, the hammer portion M will strike portion e3 of the anvil 38. This will drive the anvil 33 forwardly against the action of the spring which will return the anvil to its original position against shoulder 4i immediately after the percussive blow. Obviously, movement of the anvil in this manner produces corresponding percussion on the tool T.

The compressed air which, as previously indicated, is forced from the forward end of chamber 353 is carried through a passageway 53 formed in the anvil and leading to the tool socket 50. The tool is also provded'with a passageway P which leads to its tip. Consequently, compressed air will be forced out of the tip of the tool each time a percussive blow is struck on the anvil which carries the tool. This will blow loosened material from the hole being drilled by the tool.

In all drilling operations with a star drill or the like, as is well known, it is desirable to rotate the tool to a new position after each blow on the tool. For this purpose means is provided which is actuated by rearward movement of the rod I8 for rotating the anvil and thus the tool step by step after each blow on the anvil. It will be noted that the rear portion of the anvil has a pinion 54 formed thereon. This pinion is engaged by a gear 55, as shown b-est in Figures 7 and 8. The gear 55 is disposed for rotation in a radially extension 56 of the housing Il. The gear 55 is mounted concentrically on a ratchet member 56 which is provided with a central opening 5l through which a screw 58 is threaded, this screw extending axially through the housing extension 56 and being rotatable and axially movable in the walls thereof. The ratchet member 56 is operatively connected to the gear 55 by the usual pin and notch arrangement 59 which is the ordinary free wheeling connection. The screw 58 is mounted for sliding movement in longitudinally spaced lugs 6E] and 6I carried by the housing l I. A compression spring 62 is provided around the screw 58 between lug El and a collar 63a on the screw 58 and serves to keep member 58 in its rearwardmost position. The rear end of the screw 58 vis connected by a pin 'and slot connection 63 to the lower end of a trigger 64 which is pivoted intermediate its ends at 65 to the wall of housing II, passing downwardly through a slot 66 in the housing. The upper end of the trigger 64 extends into a longitudinally extending groove 61 formed in the surface of the rod I6.

The spring 62 keeps the rod in the position shown in Figure 1 with the upper end of the trigger 64 at the forward end of the groove 61. As the rod I6 moves forwardly the end of the trigger 64 merely slides in groove 61 until the rear end of the groove is reached. At this time the trigger 64 will be swung forwardly to the position shown in Figure 2, exerting a rearward pull on the screw 58 and causing it to rotate ratchet 56 clockwise thereby producing similar rotation of gear 55. This will rotate the anvil 38 and, consequently, the tool T. As soon as the rod I6 moves rearwardly, the forward end of groove 61 will engage trigger 64 and return the trigger to the position shown in Figure 1. Thus, during each return movement of the rod I6, the tool will be rotated. During the forward .movement of the screw 58 the ratchet member 56 is rotated counter clockwise and. therefore, will not rotate gear 55. Since the forward movement of anvil 38 is slight gears 54 and 55 will always be in engagement, merely sliding relatively.

In some cases it may be desirable to supply water or other liquid to the tool instead of merely compressed air. For this purpose the housing II is provided beyond the member with a removable tap 68 by means of which a liquid-supplying conduit may be connected to the housing.

In Figure 1 0, I have illustrated a modification of my device. The structure is almost identical with the exception that the usual solenoid Illa is provided as the power element rather than the electric motor I4. This electromagnetic arrangement will function in the usual manner to reciprocate the rod I6a. In this instance, the trigger 64a which actuates the screw 58a is located forwardly of member 26a, and cooperates with the forward end of rod I6a. However, this mechanism functions practically the same as before.

It will be apparent from the above description that I have provided a percussion tool having a number of advantages. The tool is relatively simple and inexpensive to manufacture. Since it is mechanically driven and since it produces its own air supply for blowing out the drilled hole, no hose connections to a compressor are required. Effective and simple means is provided for rotating the tool after each percussive blow.

Various other advantages will be apparent.

Having thus described my invention, what I claim is:

l. A percussion tool comprising a cylindrical housing, a tool-carrying anvil mounted at the forward end of said housing for axial movement, a rod within said housing mounted for axial movement in axially spaced guide members disposed within the housing behind said anvil, a. hammer portion on the forward end of said rod being adapted to strike a striking portion on the rear end of said anvil, a chamber being formed between said rod guide members, a pistoncarried by said rod between said guide members, said chamber being provided with an air inlet through the wall of the housing behind saidpiston and an air outlet through the forwardmost guide member, said piston being provided with an air passageway extending therethrough. and a one way valve for controlling said air passageway, said valve closing automatically upon forward movement of the piston and opening automatically upon rearward movement of the piston, said anvil being provided with an air conducting passageway extending therethrough for conducting air to a tool carried thereby.

2. A percussion tool according to claim 1 wherein said valve comprises a plate carried by pins extending axially through said piston and having the plate on one end thereof and stop means on the other end thereof for limiting movement of the plate.

3. A tool according to claim 2 wherein a compression spring is provided between each of said rod guide members and the corresponding face of the piston.

4. A tool according to claim 3 wherein mechanical means is provided within the housing for reciprocating the rod.

5. A tool according to claim 4 wherein said mechanical means includes an electric motor and crank mechanism connecting said motor to said rod.

6. A tool according to claim 4 wherein said mechanical means is operated electromagnetically.

'1. A tool according to claim 3 wherein a compression spring is provided ahead of the anvil for resisting forward movement thereof.

8. A tool according to claim 1 wherein said anvil is also mounted in the housing for rotating movement and wherein means is provided for rotating said anvil upon rearward movement of the rod, said means comprising a screw carried by the housing for axial movement, a trigger connected to the screw and moved by engagement with the rod upon rearward movement thereof, and ratchet means connecting said screw to said anvil.

9. A tool according to claim 8 wherein said ratchet means comprises a free wheeling drive between said screw and anvil. said free wheeling drive comprising an actuating member through which said screw is threaded.

CHARLES T. COLE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,867,201 Babb July 12, 1932 1,869,875 Warren Aug. 2. 1932 

